Explanation: Not a Falcon 9
rocket launch after sunset, the Cat's Eye Nebula (NGC 6543) is
one of the best known planetary nebulae in the sky.
Its haunting symmetries are seen
in the very central region of
this
composited picture, processed to reveal an
enormous but extremely faint halo of gaseous material, over three
light-years across.
Made with data from ground- and space-based telescopes
it shows the extended emission which surrounds the brighter, familiar
planetary nebula.
Planetary nebulae have long been appreciated as a final phase
in
the life of a sun-like star.
But only more recently have some planetaries been
found to have halos
like this one, likely formed of material shrugged off during
earlier active episodes in the star's evolution.
While the planetary nebula phase is thought to last for around
10,000 years, astronomers estimate the
outer filamentary
portions of this halo to be 50,000 to 90,000 years old.